Commit 1f5bd054 authored by Alexey Dobriyan's avatar Alexey Dobriyan Committed by Linus Torvalds
Browse files

proc: selftests: test /proc/uptime 

The only tests I could come up with for /proc/uptime are:
 - test that values increase monotonically for 1 second,
 - bounce around CPUs and test the same thing.

Avoid glibc like plague for affinity given patches like this:
https://marc.info/?l=linux-kernel&m=152130031912594&w=4

Link: http://lkml.kernel.org/r/20180317165235.GB3445@avx2


Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4f113437

tools/testing/selftests/proc/.gitignore

+2 −0
Original line number Diff line number Diff line
@@ -3,4 +3,6 @@ 
/proc-self-map-files-002

/proc-self-syscall

/proc-self-wchan

/proc-uptime-001

/proc-uptime-002

/read

tools/testing/selftests/proc/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -6,6 +6,8 @@ TEST_GEN_PROGS += proc-self-map-files-001 
TEST_GEN_PROGS += proc-self-map-files-002

TEST_GEN_PROGS += proc-self-syscall

TEST_GEN_PROGS += proc-self-wchan

TEST_GEN_PROGS += proc-uptime-001

TEST_GEN_PROGS += proc-uptime-002

TEST_GEN_PROGS += read



include ../lib.mk

tools/testing/selftests/proc/proc-uptime-001.c

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+45 −0
Original line number Diff line number Diff line 
/*

 * Copyright _ 2018 Alexey Dobriyan <adobriyan@gmail.com>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

// Test that values in /proc/uptime increment monotonically.

#undef NDEBUG

#include <assert.h>

#include <stdint.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>



#include "proc-uptime.h"



int main(void)

{

	uint64_t start, u0, u1, i0, i1;

	int fd;



	fd = open("/proc/uptime", O_RDONLY);

	assert(fd >= 0);



	proc_uptime(fd, &u0, &i0);

	start = u0;

	do {

		proc_uptime(fd, &u1, &i1);

		assert(u1 >= u0);

		assert(i1 >= i0);

		u0 = u1;

		i0 = i1;

	} while (u1 - start < 100);



	return 0;

}

tools/testing/selftests/proc/proc-uptime-002.c

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+79 −0
Original line number Diff line number Diff line 
/*

 * Copyright _ 2018 Alexey Dobriyan <adobriyan@gmail.com>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

// Test that values in /proc/uptime increment monotonically

// while shifting across CPUs.

#define _GNU_SOURCE

#undef NDEBUG

#include <assert.h>

#include <unistd.h>

#include <sys/syscall.h>

#include <stdlib.h>

#include <string.h>



#include <stdint.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>



#include "proc-uptime.h"



static inline int sys_sched_getaffinity(pid_t pid, unsigned int len, unsigned long *m)

{

	return syscall(SYS_sched_getaffinity, pid, len, m);

}



static inline int sys_sched_setaffinity(pid_t pid, unsigned int len, unsigned long *m)

{

	return syscall(SYS_sched_setaffinity, pid, len, m);

}



int main(void)

{

	unsigned int len;

	unsigned long *m;

	unsigned int cpu;

	uint64_t u0, u1, i0, i1;

	int fd;



	/* find out "nr_cpu_ids" */

	m = NULL;

	len = 0;

	do {

		len += sizeof(unsigned long);

		free(m);

		m = malloc(len);

	} while (sys_sched_getaffinity(0, len, m) == -EINVAL);



	fd = open("/proc/uptime", O_RDONLY);

	assert(fd >= 0);



	proc_uptime(fd, &u0, &i0);

	for (cpu = 0; cpu < len * 8; cpu++) {

		memset(m, 0, len);

		m[cpu / (8 * sizeof(unsigned long))] |= 1UL << (cpu % (8 * sizeof(unsigned long)));



		/* CPU might not exist, ignore error */

		sys_sched_setaffinity(0, len, m);



		proc_uptime(fd, &u1, &i1);

		assert(u1 >= u0);

		assert(i1 >= i0);

		u0 = u1;

		i0 = i1;

	}



	return 0;

}

tools/testing/selftests/proc/proc-uptime.h

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+74 −0
Original line number Diff line number Diff line 
/*

 * Copyright _ 2018 Alexey Dobriyan <adobriyan@gmail.com>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

#undef NDEBUG

#include <assert.h>

#include <errno.h>

#include <string.h>

#include <stdlib.h>

#include <unistd.h>



static unsigned long long xstrtoull(const char *p, char **end)

{

	if (*p == '0') {

		*end = (char *)p + 1;

		return 0;

	} else if ('1' <= *p && *p <= '9') {

		unsigned long long val;



		errno = 0;

		val = strtoull(p, end, 10);

		assert(errno == 0);

		return val;

	} else

		assert(0);

}



static void proc_uptime(int fd, uint64_t *uptime, uint64_t *idle)

{

	uint64_t val1, val2;

	char buf[64], *p;

	ssize_t rv;



	/* save "p < end" checks */

	memset(buf, 0, sizeof(buf));

	rv = pread(fd, buf, sizeof(buf), 0);

	assert(0 <= rv && rv <= sizeof(buf));

	buf[sizeof(buf) - 1] = '\0';



	p = buf;



	val1 = xstrtoull(p, &p);

	assert(p[0] == '.');

	assert('0' <= p[1] && p[1] <= '9');

	assert('0' <= p[2] && p[2] <= '9');

	assert(p[3] == ' ');



	val2 = (p[1] - '0') * 10 + p[2] - '0';

	*uptime = val1 * 100 + val2;



	p += 4;



	val1 = xstrtoull(p, &p);

	assert(p[0] == '.');

	assert('0' <= p[1] && p[1] <= '9');

	assert('0' <= p[2] && p[2] <= '9');

	assert(p[3] == '\n');



	val2 = (p[1] - '0') * 10 + p[2] - '0';

	*idle = val1 * 100 + val2;



	assert(p + 4 == buf + rv);

}

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